Considering the case when the largest ordered sample has at least \(k\)  similar symbols. Also, considering that \(L_m>>l_{n,m}\) , the expected number of similar symbols can be approximated as [1]}
\(U_{n,m,\zeta }=\sum \nolimits _{k=0}^{\zeta -1}\left[1-\lbrace F(k)\rbrace ^{L_{m}-\zeta }\right].\) 
